The Ugong language is an endangered Tibeto-Burman language of Western Thailand, spoken in isolated pockets in Uthai Thani and Suphanburi provinces.

There are around 500 ethnic Ugong people and 50 speakers of the Ugong language. There are also many Lao Krang people living in the Gong areas.

The ethnic group was first known to Westerners in the 1920s, when the language was already considered in severe decline . In the 1970s, David Bradley began working on the language in the several areas where it was still used, by which time it was already extinct in two of the locations given by Kerr about 50 years earlier.

The last children speakers were in the 1970s, and the children now speak Thai as their first language. The people were then forced from two of these villages when the Electricity Generating Authority of Thailand built dams over the Kwae Yai and Khwae Noi River . Because of the displacement of the people of an already declining language, the language is considered especially vulnerable to extinction.